13073406921 has 9 divisors (see below), whose sum is σ = 18884305479. Its totient is φ = 8715375936.

The previous prime is 13073406919. The next prime is 13073406923. The reversal of 13073406921 is 12960437031.

The square root of 13073406921 is 114339.

It is a perfect power (a square), and thus also a powerful number.

13073406921 is a `hidden beast` number, since 1 + 307 + 340 + 6 + 9 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (13073406919) and next prime (13073406923).

It can be written as a sum of positive squares in only one way, i.e., 7498694025 + 5574712896 = 86595^2 + 74664^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 13073406921 - 2¹ = 13073406919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13073406923) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 323961 + ... + 362073.

Almost surely, 2^13073406921 is an apocalyptic number.

13073406921 is the 114339-th square number.

13073406921 is the 57170-th centered octagonal number.

It is an amenable number.

13073406921 is a deficient number, since it is larger than the sum of its proper divisors (5810898558).

13073406921 is an frugal number, since it uses more digits than its factorization.

13073406921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76232 (or 38116 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

Multiplying 13073406921 by its sum of digits (36), we get a square (470642649156 = 686034²).

The spelling of 13073406921 in words is "thirteen billion, seventy-three million, four hundred six thousand, nine hundred twenty-one".